Automatic ignition and control mechanism for oven burners



May 5, 1953 R. PERL ETAL AUTOMATIC IGNITION AND CONTROL MECHANISM FOR OVEN BURNERS Filed Dec. 10, 1.95].

'7 Sheets-Sheet l IN V EN TORS Richard L. Fer/ 9.70/7 M Hoff 4%. a imzzb May 5, 1953 R. L. PERL ETAL 2,637,336

AUTOMATIC IGNITION AND CONTROL MECHANISM FOR OVEN BURNERS Filed Dec. 10, 1951 7 Sheets-Sheet 2 Lf fy IN VEN TORS May 5, 1953 R. L. PERL ETAL 2,637,336

AUTOMATIC IGNITION AND CONTROL MECHANISM FOR OVEN BURNERS Filed Dec. 10, 1951 7 Sheets-Sheet 5 I I f I m5 r INVENTORS J Fz'chcl/"L Per/ g BY (9J0 /7/7 N-fiaff May 5, 1953 R. PERL ETAL 2,637,336

AUTOMATIC IGNITION AND CONTROL MECHANISM FOR OVEN BURNERS Filed Dec. 10, 1951 7 Sheets-Sheet 4 9 /fl--- 98 9 95 .3 L

INVENTORS f5 F/c hard L. Per/ BY 9 0/7/1 MHaff May 5, 1953 L. PERL ET AL R. AUTOMATIC IGNITION AND CONTROL MECHANISM FOR OVEN BURNERS Filed Dec. 10, 1951 '7 Sheets-Sheet 5 /02- &5 94 5,2

INVENTORS Jff fi'zq'hard A. Perl BY J0/7r1/V. Huff y 1953 R. L. PERL ETAL 2,637,386

AUTOMATIC IGNITION AND CONTROL MECHANISM FOR OVEN BURNERS Filed Dec. 10, 1951 .7 Sheets-Sheet 6 I 2& 2'8 5/ FF M @J I a INVENTORS J?? 7 Flt/10rd L Pf/ BY 9 JO/H7 N, I /Of? n- 1447mm May 5, 1953 R. L. PERL ET AL 2,637,386

AUTOMATIC IGNITION AND CONTROL MECHANISM FOR OVEN BURNERS Filed Dec. 10, 1951 7 Sheets-Sheet '7 2a //3 il lit) J fl 98 f9 INVENTORS Plum/"d .4. Per/ BY 9 John N. Hoff Patented May 5, 1953 o STATES PATENT OF F [C Ohio" ApplicationDec'ember 10, 1951', SerialNo. 260,902

1 19 Clairns.

This invention relates to an'autom'atic electric ignitionand control mechanism for-cooking range burners using gaseous fuel ancl is a modification of -the control mechanismshownin the co-pend ing application of Charles M-.Mayer and John M; Hoff filed. April 3,1950, Serial No; 153,664; new Patent N 0. 2,577,787. It is especially designed an i adapted. for automatically igniting-- and controllinghthe operation of oven'burners-in cooking ranges, and maybe used inconjunction with a time control mechanismor'independently thereof a-sdesirerl.

The-mechanism is design-ed.- -for 'use witha main gaseous fuel burner Which-is aolapteai to lie ignited by a gaseous fuel pilot-burner; As long as the pilot burner is ignited-it-isimn terialwvhether or not the main burnerburnsconstantlyl It may be extinguisl'iea ter some reasorn but it will he promptlyre-ignited by the pilot -burner if fuel is supplied thereto. But if the pilot-burner is extinguished for any reason while the main control valve is still open-to supply gas to'the main burner a; verydangerous" situation sometimes arises; Let'us assume that both-thepilot burner and themainburner areextinguished during operation' for some reason. Gas can then flow-"to the main burner but'since-the pilot-burner is eXtinguishecL-themain hurner will not he ignited and unburned gas Will acouinulatein the'oven which may violently explode when an attempt is made to ignite eitherthe -main-or-pilot burner. It has been foundt by experience that both"the pilot burner anclthe main burner are frequently extinguished. during use while -th e main control valve is open to supply gas-to'themain'burner. This is sometimes due to amomentarylailureof the gas supply orthe slammingeoi the oven'cloor or to various other reasons.

In order to prevent any'acc'umulation of un-' burned gas and thus eliminate anydanger of an explosion therefroni in' "the "event "the pilot burner is"extinguishe'd for any'resmrwiine the control" valve "is" still set to supply gas'to "the main 1 burner; we provide in" our -improved ratus safety control mechanism by Which the supply oi "gas-to 1 botli' urennaih burner the pilot i'burner' is completely out os;=' -1ndss@nsent1-y of the- -maincontrol-valve; in th event 'the pilot burner is extinguished ifor any" reason while -'-th'e main gas control valve is open Ourimproved apparatus includes a main gaseous fuel burner by which the ovenin a cook: ing range is heated; Themain burner is adapted to" be ignited by a gaseous fuel pilot-burner which burns only during the time the oven is inopera: tion. At other times the 'supplylof gas to both the" main'burner'and the pilot burne r is cut oil 2" .7 by a 'main control valve and asafety control valve mechanism-which are interposed" in a" conduit between-the gas supply manilolrlanclthe burners. (hen the main control valve is open gas will fiowfrom the maniioldinto asalety control valve mechanism; From: the safety control: valve mechanism gas wilrflow through a small branch concluitdirectly to the pilot 'burner'rand' through the mainr conduit, thB'IllELlH'COl'ltlOl valve an'd'a standard thermostatically operated oven temperature control valve to-the main burner. A normally open master control switch "which is operatively associated with themain control valve isarrangecl'to he closecl'by' theopening'of the main control valve antl'to be op'enedt'by'tlieclosingot the main control valve;: The closing 01 the master control switch, asthe main control valve is openedto supply'gas to theirnain-burner, energizes through: a normally closed"thermo= statically operateol switchy an electric resistance ignition element and a-, solenoid 'which'ispperatively connected to the safety control valve mechanism; The energizatioirof th'e"s0lenoid causes it to operate the safety control v'alve mechanism to permit the flow of gas to the pilot burner while cuttingoff the supply of'gasto'the main burner. The" pilot burner is ign'itedby the electric ignition elementand'proj'ectsa' fi'arii'e against a thermostaticelement, which controls the operation of the normally closedswitch; and against a thermocouple which is operativelycon nectecl to the-safety control valvemechanisuii After the thermostatic "element becomes heated it opens the normally-closedswitch-whichde ene ergizes the electricignition element and th'e'sole noicl. Assoon as the *solenoictisde energizetl the'safetycontrol mecha ismis'autorhaticallyop erated by spring rneans to supplygas-"tmthe mainburnerthrough the main control valve anolthe oven temperature control valve. The burner is then ignited pythe Qllqll bllllflqll. The thermocouple, as'iong as itis heated Joy the pilotbii e'r maliit ai stl'ieisaiety' controljvalve tain "the" desired ov the 'pilotburner"is ignited tlie I burn normally untler the' control of" the? over temperature control valve "until the 'maiiri control valve is manually turned off? But ifduring op oration the pilot burner isextinguished "for "any reason the thermocouple;Will-"immediately cool anri1allo vv the safety control valve mechanism 'to automatically cut oftthe supply of gas-to loath the main burner and the pilot burner. As an example of the manner of operation of the apparatus, let us assume that during operation the pilot burner is suddenly extinguished, for instance, by a momentary failure of the gas supply from the manifold to the burners. The thermo couple immediately cools, allowing the safety control valve mechanism to cut on communication between the manifold and both the main burner and the pilot burner. The main control valve is still open and the master switch closed. Then after the thermostatic element has cooled, closing the normally closed switch, which is maintained open by the thermostatic element during normal operation of the oven, the electric ignition element and the solenoid are again energized. The energization of the solenoid will cause it to operate the safety control valve mechanism to establish communication between the manifold and the pilot burner only. Then when gas is again available the pilot burner will be ignited and re-establish normal operation of the oven as previously described. In the event of a power failure during normal operation of the oven, the main burner will continue to operate normally under the control of the oven tempera ture regulator valve until the burner is turned off by the main control valve, assuming of course that the pilot burner continues to burn. In the event of a power failure before gas is turned on by the main control valve, the pilot burner can be manually ignited as will be hereinafter explained. The supply of gas to both the main burner and the pilot burner will then be con trolled by the pilot burner through the thermocouple and safety control valve mechanism as previously described.

In order to extinguish the pilot burner when the operation of the main burner is terminated by the closing of the main control valve, we provide an interrupter switch in the circuit between the thermocouple and the safety control valve mechanism. This switch is located in the same casing as the master control switch and is opened and closed by the closing and opening of the main control valve simultaneously with the opening and closing of the master control switch. Then when the manually operable main control valve is closed to cut off the supply of gas to the main burner, the interrupter switch is simultaneously opened, breaking the circuit between the thermocouple and the safety control valve mechanism which permits the safety control valve mechanism to out off the supply of gas to both the pilot burner and the main burner.

When it is desired to use the apparatus in conjunction with any standard time control mechanism, we provide a supplemental master switch and a supplemental interrupter switch which are simultaneously opened and closed at predetermined times by the time control mechanism. The supplemental master switch is inserted in the main circuit controlled by the primary master switch, and the supplemental interrupter switch is inserted in the thermocouple circuit controlled by the primary interrupter switch. In use the time control mechanism is set to initiate operation of the oven burner at a predetermined time and to terminate operation thereof at a predeter mined later time, after the main control valve has been turned on for automatic operation which closes the primary master switch and the primary interrupter switch. Then when the supplemental switches which are now in series with the primary switches are closed by the time control mechanism the apparatus will function in the same manner as previously described.

During a prolonged power failure one may desire to use the oven several different times. In order to eliminate the necessity of either keeping the burner operating constantly during a prolonged power failure or manually setting the safety control valve mechanism and lighting the pilot burner with a match each time it is desired to use the oven, we provide means whereby the pilot burner will burn constantly and will not be extinguished each time the main burner is turned off by the closing of the main control valve. In this case the circuit between the thermocouple and the safety control valve mechanism will not be broken when the main control valve is turned off to stop operation of the main burner, so that the safety control valve mechanism will remain in condition to always admit gas to the pilot burner and to the main burner whenever the main control valve is opened. If under this condition the pilot burner is extinguished for any reason the thermocouple will cool and the safety control valve mechanism will then cut off the supply of gas to both the main burner and the pilot burner.

The principal object of the invention is to provide an improved electrical ignition and automatic control system for cooking range oven burners using gaseous fuel.

Another object of the invention is to provide in an electrical ignition and control system of the character described improved means for completely shutting off the supply of gas to both the main burner and the pilot burner in the event the pilot burner becomes extinguished for any reason before the supply of gas to both the main burner and the pilot burner is cut off by the main control valve.

Another object of the invention is to provide an oven burner ignition and control system of the character described wherein the pilot burner may be arranged to burn only when the main burner is turned on or to burn constantly if desired.

Still another object of the invention is to provide an improved electrical ignition and control system of the character described which may be used in conjunction with a time control mechanism or independently thereof as desired.

Other and more limited objects of the invention will be apparent from the following specification and the accompanying drawing forming a part thereof, wherein:

Fig. 1 is a diagrammatic view illustrating my improved electrical ignition and safety control mechanism as applied to a cooking range oven burner using gaseous fuel;

Fig. 2 is an enlarged central longitudinal vertical section through the safety control valve mechanism showing the various parts in the position they assume when the oven burner is turned off;

Fig. 3 is a view similar to Fig. 2 showing the various parts in the position they are automatically moved to when the main control valve is first turned on to initiate the operation of the main oven burner;

Fig. 4 is a wiring diagram showing the switches and the main control valve in off position;

Fig. 5 is a view similar to Fig. 4 showing the switches and the main control valve set for manual control of the main burner;

Fig. 6 is a view similar to Fig. 4 showing the position.

switches and main control valve set for automatic control of the main burner;

Fig. '7 is a view similar to Fig. 4 showing the switches and the main control valve set for the pilot burner to burn constantly;

Fig. 8 is a view similar to Fig. 4 showing a slightly different means for maintaining the pilot burner burning constantly; and

Fig. 9 is a detail section taken on the line -9 of Fig. 1.

Referring now to the drawings by reference characters, the numeral 1 indicates a gaseous fuel burner which is mounted in or in heating relation to a cooking range'oven 2. Gaseous fuel is supplied to the burner I from a manifold M through a conduit 3. Interposed in the conduit 3 are a safety control valve mechanism generally indicated by the numeral 4, a manually operable main control valve 5, and an oven temperature control valve 6. The main control valve 5 is a plug valve of standard construction which when in open or on position permits the flow of gas through the conduit 3 from the manifold M to the burner i, and in closed or off position cuts on flow of gas to the burner 1-. This valve is manually opened and closed by a handle a and a valve stem 3;, and directly controls the operation of the entire apparatus in that it initiates the operation of the entire apparatus when it is turned to an on position and ter.nl-

nates the operation when it is turned tothe off From the manifold M gas flows through the-conduit 3-to the safety-control valve mechanism 4, to be described in detail hereinafter. From the safety control valve mechanism i 4 the gas flows through the conduit 3', the main control valve 5, the oven temperature control valve-6 to the burner I. Theoven temperature control valve 6 is operative to regulate the amount of gas flowing to the burner in order to maintain the oven atany desired set temperature. The valve 6 is set to any'desired temperature by a handle H having a pointer is which cooperates with a graduated dial it carried by the valve it; The valve 6 is controlled according to the-temperature setting-by a thermostatic element it which is mounted in. the oven 2 and is connectedto the valve-5 as shown at l5. The oven temperature control valve '6 is of standard well known construction. Consequently it is'not'shown in detail herein. There are many different constructions available any one of which will work equally well herein. Gas is also suppliedto a pilot burner is through a branch conduit H whichextends between the safety control valvemechanism 4 and the pilot burner 16-. Thepilotburner It is disposed adjacentthe rear end of the -main burner l in position to ignite the burner i when gas is supplied thereto. An electrical ignition element it is operatively associated with the pilot burner 55 inpositi'on to ignite the pilot burner 85 when gas is supplied thereto. A thermostatic element 19 and a multiplethermocouple-20ers mounted in position to be heated by a flame'from the pilot burner. The thermostatic elementlil' is opera.- tive to open and close a switch 2-! which controls theenergization of the electricalignition element l3 and a solenoid 22which when energized operates the safety control valve mechanism to supply gas to the pilot burnerl6 as will bedescribed in connection with the description of the safetycontrol valve mechanism-andthe operation of the whole apparatus. The thermocouple 20- when heatedis operative to holdjthe safety control valve mechanism in condition to maintain the supply of gas to both the pilot burner is and the main burner I, as will also be described in connection with the description of the safety control valve mechanism and the operation of the apparatus. A master control switch 23 which is associated with the main control valve 5 is adapted to be opened and closed simultaneously with the closing and opening of the main control valve 5. As the control valve 5 is turned from the on or closed position to on or open position the master control switch 23 is moved from the open position toone closed position by the main control valve stem 8. Conversely, when the main control valve 5 is turned from openor on position to closed or off position the switch 23 is moved from closed positionto open position.

An electric circuit between the thermocouple 29 and the safety control valve mechanism 5 is established by a copper tube 26 which encloses an insulated wire '21. The wire 21 is severed between the thermocouple and the safety control mechanism It and an interrupter 28'having terminals 29 and 3B is. interposed between the severed ends. One of the severed ends of the wire 2? is connected to the terminal-121s and the other severed end is connected to the terminal 3t. The purpose and function-of the interrupter 28*will be explained in detail in connection with the description of the operation of the apparatus.

The construction of the safety control valve mechanism 5 and its connection to the solenoid 22 will now be described, reference being had to Figs. 2, 3, and dot the drawing. This mechanism comprises a casing having achamber 36 in one end thereof and a chamber 31 in the other end thereof. The chambers. 36 and 31 are connected by a bore 38 of reduced diameter. A valve seat 39 is located at one end of the bore 38 and a similar valve seat 40 is located at the other end of'theboro 38. The chambertfi is closedbyaremovable cap 4| and'the chamber 31- is closed by a removable cap 42. A sleeve 43, having end walls 44' and 45, is carriedby the cap' 41' and extends into the chamber 36. A valve stem 46 which is slidably mounted in a bushing 41 carried by the end wall of the sleeve 43, extends from the chamber 36 into the sleeve 43. A valve disc 48 of suitable material issecured-to oneend of the valve-stem 45 within the chamber 36} and a metal disc 49 is secured to the other end of the stem 46 within the sleeve- 43. A spring 50" disposed about the-valve stem 46 between-the valve-disc 4B'and the" end wall 45 of' the sleeve 43- normally holds the-valve disc 48 against the-valvoseat 39; A horseshoe magnet'5l is secured to one end of a hollow exteriorly-thread'ed stud-52 which extends out throughaligned apertures in'the end wall 44, ofthe sleeve 43; and in the-end-of th'e'capAI; A nut. 53 screwed onto theouter portion of the stud 52 securely holds the magnet 5| and the sleeve43 in place.- The legsof the magnet 5! have a winding 54 thereon one end of which is connected tothe tube- 26- and the other end of which isconnected to the= wire Z'T-in the tube-2 61 The tube 26. isinserted intothe liollow-stud 52 andis. held. in: place by a screw fitting 52a. A sleeve 55 is screwed::into threaded recess in the end of the cap 2;.asindicated.ati56. and-extends into tho-chamber 31 a' slight distance; Oneiend of the sleeve 55 is closed by; an end wall'51, and the other end which .is- .open-registers witl'raacircular. aperture 58 inthe end wall ofthecap-M; Aplug 59 is slidabl-y mounted inthe sleeve; 55 and extends-out through-the aperture 58 in the cap 42; A stem 62 which issecuredto the-inner end of the plug 59' extends out through an aperture 63, in the end wall 51 of the sleeve 55, and through the chamber 31 and into the bore 38. The stem 62 has a collar 64 rigidly secured thereon between the end wall 51 and the outer end of the stem. A valve disc 65 of suitable material is slidably mounted upon the stem 62 between the end wall 51 of the sleeve 55 and the collar 64. The valve disc 65 is adapted to engage the valve seat 40 to out 01f the flow of gas into the chamber 3! during the initiation of operation as will be hereinafter described. A compression spring 66 disposed about the stem 62 between the end wall 51 and the valve disc 65 normally yieldingly holds the valve disc 65 against the collar 64. A compression spring 61 which is stronger than the spring 66 is disposed about the stem 62 within the sleeve 55 between the inner face of the end wall 51 and the inner end of the plug 59. The spring 61 is operative to return the plug 59, stem 62 and valve disc 65 from the position shown in Fig. 3 back to their normal position as shown in Fig. 2, against the resistance of the spring 66. A port 68 in the casing 35 provides communication between the chamber 36 and the conduit 3 to allow gas to flow from the manifold M through the conduit 3 into the chamber 36. During normal operation of the main burner I gas flows from the chamber 36 through the reduced intermediate bore 38 and into the chamber 3?. A port 69 which establishes communication between the conduit I1 and the bore 38 is provided to supply gas to the pilot burner I6; and a port 10 establishes communication between the chamber 31 and the conduit 3 to permit the flow of gas from the chamber 3! to the main burner I through the main control valve, and the oven temperature control valve.

The solenoid 22 may be connected to the safety control valve mechanism 4 in any desired suitable manner. As shown herein it is secured to the cap 42 of the safety control valve mechanism with armature thereof connected directly to the plunger 59 of the safety control valve mechanism.

The master control switch 23 which is mounted in a casing 25 secured to the main control valve 5 about the valve stem 8 comprises the arm 15 which is connected to the stem 8 of the manually operable main control valve 5 for rotation therewith, and the two contacts F5 and I! which are spaced 180 apart and are adapted to be selectively engaged by the arm 15 when it i rotated 90 in either direction from its normal off position. The interrupter switch 24 which is also mounted in the casing 25 comprises the arm 18, which is connected to the valve stem 8 of the manually operable main control valve 5 for rotation therewith, and the two contacts 19 and 80 which are adapted to be selectively engaged by the arm I8. The contact 19 extends through an arc of 45 so that the arm 18 will engage the contact 19 upon 45 rotation of the valve stem 8 in a clockwise direction from the normal off position of the valve 5 and will remain in contact therewith during the next 45 rotation of the valve stem 8 in a clockwise direction. When the valve stem 8 is rotated in a counter-clockwise direction from the normal off position of the main control valve 5 the arm 18 will engage the contact 80 upon 90 rotation of the stem 3.

In order that the operation of the burner I may be automatically initiated at a predetermined set time and terminated at a predetermined set later time, we provide a supplemental master switch 82, a supplemental interrupter switch 83 and a standard time control mechanism 84 which includes a. self-starting electric clock 85 and is operative to open and close the supplemental switches 82 and 83 at predetermined set times. We also construct the manually actuated main control valve 5 so that it can be opened by turning the valve stem 8 through in either direction from normal off position. For manual control the valve stem 8 is turned in a clockwise direction and for automatic control it is turned in a counter-clockwise direction. A finger 86 secured to the valve stem 8 is adapted to engage a stop 81 when valve 5 is set for manual control and a stop 88 when the valve is set for automatic control. A stationary dial 89 behind the valve handle I and a cooperating pointer 90 carried by the handle I indicate the setting of the valve 5.

The supplemental master switch 82 comprises the contacts 93 and 94 which are adapted to be bridged by a conductor bar 95; and the supplemental interrupter switch 83 comprises the contacts 91 and 98 which are adapted to be bridged by a conductor bar 99. The conductor bars 95 and 99 are adapted to be moved toward and away from the contacts 93, 94, 9'! and 98 at predetermined times by the time control mechanism 84 through a connecting link I00.

The operation of the apparatus will now be described in connection with Figs. 4, 5 and 6. For manual control of the burner I the main control valve is opened by turning the valve stem 8 in a clockwise direction 90 by the handle I, which moves the master control switch 23, the interrupter switch 24 and the main control valve 5 from their normal off positions as shown in Fig. 4 to the positions shown in Fig. 5 with the switch arm 7 5 engaging the contact 16 and the switch arm I8 engaging the contact 19. Current will now flow from one side IOI of the line through the lead I02, switch arm 75, contact 16 and lead I03 to the normally closed thermally opened switch 2|. From the switch 2I the current flows through the lead I04 to the solenoid 22 and from there back to the other side I05 of the line through the lead I06. Current also flows from the switch 2I through the leads I04 and I9! to the electric ignition element I8 and from there back to the side I05 of the line through the leads I08 and I06. The solenoid 22 and the ignition element I8 are now energized. The solenoid 22 being energized shifts the various parts of the safety control valve mechanism from the positions shown in Fig. 2 to the position shown in Fig. 3. Gas can now flow to the pilot burner I6 where it is ignited by the ignition element I8, but it cannot yet flow to the main burner I since the valve mechanism in the chamber 37 of the safety control valve mechanism is maintaining the entrance thereto closed. The pilot burner being ignited heats the thermocouple 20 and the thermal element I9. The thermocouple being heated generates a minute current of the order of 200 to 250 millivolts which flows from the thermocouple through the tube 26 to the winding 54 of the electromagnet SI and. from there through the wire 21 to the terminal 30 of the interrupter 28. From the terminal 30 the current flows through the lead I 09, contact I9, switch arm 78 and lead IIO to the terminal 29 of the interrupter 28, and from there back to the thermocouple 20 through the wire 21. The thermocouple current energizes the electromagnet 5I sufiiciently for it to hold the valve mechanism in the chamber 36 in the position shown in Fig. 3 after it has been moved to this position 9. byzthesolenoid 2 2, but-noteenough- .for r theelectromagnet to attractthe: mechanism from the positionsshown in Fig. 2 .to the position shown irr'cliig: 3'. :The rhea-ting of: the thermal element |!9"C2J1S6S1= it "to i open the normally closed switch 2 I-wvhir'zh breaks the circuit to and ide energizes the-:zsolenoid .22 arrel the ignition= element i58 As soon as thesolenoidflz is-de-energized the spring Bl-meturns the valve. mechanism. in. the chamber 31' backlfronithe position shown fin-Fig. 3- to the position'shown in -Fig.-2 while-the electromagnet 5 I-- holdszthe mechanism ini-the chamber 3% in the. position shownin Fig. 3. Gas cansnow iiow to theimain burner l where itissignited by pilotrburner 4-5. Under normal conditions the burner lwill-i now operate i under control of the oventemperature control=valve .6 until its operation ris terminated by the manual closing .of thenmain control valve 5 which cuts off the suplnlyof-gas to .themain-burner andreturns the-switchesiS: and M .to open positionas shown in -Eigw. .The opening of'the interrupter switch 24 breaksthe thermocouple circuit and deenergizes the electromagnettl after which the spring 50 returns the mechanism in the chamber 3.6 fromth'ezposition shown in-Fig. 3 to the positio'n'shownin. Fig 2, thuscutting off thesupply ofgasnto the-pilot burner. If-the pilot burner issextinguished-for any reason during operation then thewthermocouple '24] and the thermal element' tll will cools The electromagnetwill thenfbe desenergizedl and release-the mechan in rtheichamber-v36-which-will then be returned bythespring 50 to the position shown inFig. 2

cutting off-thesupply of gas to both the pilot burner I! and-the .main humor I. When the thermal element 13 cools,v which is after the thermocouplehas cooled;theswitch 2.! will close. The-apparatus will then recycle as described. as SOOI'l -aS igas-is available.

For automatic control of the burner l the main control valve 5 I and the switches and'. 2e are @set as shown in-Fig. 6 by turning the valve stem- 8-counter-clochwise through 90 from the normal oir position asshcwnein-Fig. l} and the time control mechanism E l-is set to-close the supplemental. switches-Bland 83 at the desiredtime and torecpenthemat-the .desired'latertime. lZ-he switches zfliand 82in themain circuitare nowin series with each other-,- andthe switches-Mi andl83 incthe' thermocouple circuit-areealso in .series with each other. When the time. control mechanism 8t closes the supplemental switche'sllan'd 153 current will flow ircmfithe: side -it! of .the .line

through-the lead lllll switch arm 3.15,. contact 11,

lea-d ill-,switch-M-a and IeadsUlLZ andJlEB to the normally closed .switchdlll. :Frornthe switchnzl' theicurrent will zflow throughithe.solenoid ZZIand the ignition-element l8 andbaclc-to the other side 1 Eli orthe line. :l'n the thermocouple circuit current willflowthrough'the tubeflfi winding 5t and wireizlto the-terminal so; Fromthe-terminal 36 the acurrent will flow through the leads 409 and l is, \switch .fia lead .ll l,-.contact .88. switch armlfivand lead Mfi toithe terminal fl-ll and from there throughthewire al back to the thermocouplerzil. Thetapparatus willnow-function asdescribed in connection with manual control until thetime,

control.- meehanismopens "the switches--32 and 83 which-breaks the'main:andrthethermocouplecir cuits, thus terminating operation .aspreviously described. v

In.ordei tooperate-the. mechanism with anonstantly burning pilot burner during a prolonged power .iailure, we set the switchesis and 12B. and

the-main controlvalve 5 inoffposition as shown in Fig. 7 which ismidway between thepositions shown in Figs..4.and.5, In thisposition the'interrupter switch E lis closed and the main control valve 5 is still closed. We then manually depress the plunger 59 to set the safety control valve mechanism as shown in Fig. 3 and light the pilot bnrner with-a match. After the thermocouple has been heated by the pilotburner we release the plunger 59 allowing the mechanism'in the chamber 3'! of the. safety control valve mechanism i to return to the position shown in Fig. 2' while the electromagnet 5! retains the mechanism in the chamber 36 in the position shown in Fig. 3. Gas willnow be constantly supplied to the pilot burner but it cannot be supplied to the main burner until the main control valve 5 is opened by turning the valve stem 8 45 furtherin'a' clockwise direction. After the valve '5- h'asbeen opened gas will be supplied to the main burner and be ignited by the pilot burner. In order'to prevent opening of the switch Ml by turning the valve stem 8 too far ina counter-clockwise'directionwhen closing the valve 5 and thus extinguish ing' the pilot burner by breaking thethermocouple circuit, we provide a pivoted detent I I5 wn-ichmay" be swung intoposition to be engaged bythe'fing'er as shown in Fig. 9, and limit the movement of thevalve stem 8 when closing the valve 5.

Anuother way of providing a constantly burn ing pilot light during a prolonged power failure is to interpose a'manually operable switch IB'B between the leads lBQjand! ill of the thermocouple circuit as shownjini Fig. 8. The switch" W5 is independent of all*the' other switches in the apparatus and is close'donly when a constantly burning pilot burner is desired. When the'switc'hi it is used the switch M is constructedas shown in Fig. 8 and the detent H5 is eliminated. Obviously thetime control cannot be used during a power failure. 7

From theforegoin'g' it willbe apparent' to those skilled in this art that we have provided a ver-y simple and efficien-t mechanism for accomplishing the objects of the invention.

'It is to beunderstood'that we are 'not limited to the specific construction shown and described herein as various modifications may be made therein within thescope of the appended claims.

. What is claimed is:

1. In an automatici'gnition and cont'rol apparatus of the character described the combi'nation of a main burner, a pilot burner'nperative to ignite saidrnain burner, an electric ignition element operative when energized to ignites'aid pilot burner, a gaseous fuel supply manifold, a main conduit through which fuel is supplied to said main burner from said manifold, a' man'- ually operable control valve interposed insai'd conduit between .saiclinain burnerandsa'id manifold, a safety control valve mechanism operative to cut on the supply of fuel to said main burner and said pilot burner interpose d' in said conduit between said manually operable control valve and. said manifold. a secondary "conduit extending'between said safety control valve mechanism and said'pilot burner throughwhich fuel is supplied to said pilot'burner, a solenoid opera tively connected. to said safety control valve mechanism, said solenoid being operativefupon energiaation to first setsaid safety control valve mechanismincondition'to supply fuel-to saidpilot burner while cutting off the supply of fuel to said-main burner and then upon subsequent de' energizaticnto set said safety control valve mechanism in condition to also supply fuel to said main burner, an electromagnet associated with said safety control valve mechanism and operative when energized to maintain said safety control valve in said last set condition, a thermocouple adapted to be heated by said pilot burner, an electric circuit between said thermocouple and said electromagnet through wh ch said magnet is energized by said thermocouple when said thermocouple is heated. an interrupter switch interposed in said circuit and operative to open and close said circuit and thereby control the energization of said electromagnet, operative connections between said manually operable control valve and said interrupter switch through which said interrupter switch is closed and opened by the opening and closing of the manually operable control valve, a normally open master switch associated with said manually operable control valve, operative connections between said manually operable control valve and said master switch through which said master switch is closed by the opening of said main control valve and is opened by the closing of said main control valve. said master switch being operat ve when closed to energize said solenoid and said electric ignition element, a normally closed switch disposed in series with said master switch which is operative when opened to de-energize said solenoid and said electric ignition element, a thermostatic element adapted to be heated by said pilot burner and operative when heated to maintain said normally closed switch open and when cool to maintain said normally closed switch closed, and means operative to maintain said thermocouple circuit closed while said manually operable control valve is closed.

2. An automatic ignition and control apparatus as defined in claim 1 in which said means comprises a manually operable switch interposed in said thermocouple circuit in parallel with said interrupter switch and independent thereof.

3. An automatic ignition and control apparatus as defined in claim 1 in which said means is associated with said manually operable control valve and said interrupter switch and is operative to limit the closing movement of said manually operable control valve and the opening movement of said interrupter switch.

4. An automatic ignition and control apparatus as defined in claim 1 in which said means includes a detent operatively associated with said manually operable main control valve and said interrupter switch and which may be moved into and out of operative position and when in operative position limits the closing movement of said manually operable control valve and the opening movement of said interrupter switch.

5. In an automatic ignition and control apparatus of the character described the combination of a main burner, a pilot burner operative to ignite said main burner, an electric ignition element operative when energized to ignite said pilot burner, a gaseous fuel supply manifold, a main conduit through which fuel is supplied to said main burner from said manifold, a manually operable control valve interposed in said conduit between said ma n burner and said manifold, a safety control valve mechanism operative to cut off the supply of fuel to said main burner and said pilot burner interposed in said conduit between said manually operable control valve and said manifold, a secondary conduit extending between said safety control valve mechanism and said pilot burner through which fuel is supplied to said pilot burner,

a solenoid operatively connected to said safety control valve mechanism, said solenoid being operative upon energization to first set said safety control valve mechanism in condition to supply fuel to said pilot burner while cutting off the supply of fuel to said main burner and upon subsequent de-energization to set said safety control valve mechanism in condition to also supply fuel to said main burner, an electromagnet associated with said safety control valve mechanism and operative when energized to maintain said safety control valve in said last set condition, a thermocouple adapted to be heated by said pilot burner, an electric circuit between said thermocouple and said electromagnet through which said magnet is energized by said thermocouple when said thermocouple is heated, an interrupter switch having two closed positions interposed in said circuit and operative to open and close said circuit and thereby control the energization of said electromagnet, operative connections between said manually operable control valve and said interupter switch through which said interupter switch is closed and opened by the opening and closing of the manually operable control valve, a normally open master switch having two closed positions associated with said manually operable control valve, operative connections between said manually operable control valve and said master switch through which said master switch is closed by the opening of said main control valve and is opened by the closing of said main control valve, said master switch being operative when closed to energize said solenoid and said electric ignition element, a normally closed switch disposed in series with said master switch which is operative when opened to deenergize said solenoid and said electric ignition element, a thermostatic element adapted to be heated by said pilot burner and operative when heated to maintain said normally closed switch open and when cool to maintain said normally closed switch closed, a supplemental master switch disposed in series with said master switch and said normally closed switch when said master switch is in one of its closed positions, a supplemental interrupter switch interposed in said circuit in series with said interrupter switch when said interrupter switch is in one of its closed positions, and a time control mechanism operative to simultaneously close and open said supplemental master switch and said supplemental interrupter switch at predetermined set times.

6. In an automatic ignition and control apparatus of the character described the combination of a main burner, a pilot burner operative to ignite said main burner, an electric ignition element operative when energized to ignite said pilot burner, a gaseous fuel supply manifold, a main conduit through which fuel is supplied to said main burner from said manifold, a manually operable control valve interposed in said conduit between said main burner and said manifold, a safety control valve mechanism operative to cut off the supply of fuel to said main burner and said pilot burner interposed in said conduit between said manually operable control valve and said manifold, a secondary conduit extending between said safety control valve mechanism and said pilot burner through which fuel is supplied to said pilot burner, a solenoid operatively connected to said safety control valve mechanism, said solenoid being operative upon energization to first set said safety control valve mechanism in condition to supply fuel to said 13 pilot burner while cutting off the supply of fuel to said main burner and then upon subsequent de-energization to set said safety control valve mechanism in condition to also supply fuel to said main burner, an electromagnet associated with said safety control valve mechanism and operative when energized to maintain said safety control valve in said last set condition, a thermocouple adapted to be heated by said pilot burner, an electric circuit between said thermocouple and said electromagnet through which said magnet is energized by said thermocouple when said thermocouple is heated, an interrupter switch interposed in said circuit and operative to open and close Said circuit and thereby control the energization of said electromagnet, operative connections between said manually operable control valve and said interrupter switch through which said interrupter switch is closed and opened by the opening and closing of the manually operable control valve, a normally open master switch associated with said manually operaole control valve, operative connections between said manually operable control valve and said master switch through which said master switch is closed by the opening of said main control valve and is opened by the closing of said main control valve, said master switch being operative when closed to energize said solenoid and said electric ignition element, a normally closed switch disposed in series with said master switch which is operative when opened tode-energize said solenoid and said electric ignition element, means responsive to said pilot burner and operative to maintain said normally closed switch open while said pilot burner is ignited, and means operative to maintain said thermocouple circuit closed while said manually operable control valve is closed.

7. An automatic ignition and control apparatus as defined in claim 6 in which said means comprises a manually operable switch interposed in said thermocouple circuit in parallel with said interrupter switch and independent thereof.

8. An automatic ignition and control apparatus as defined in claim 6 in which said means is associated with said manually operable control valve and said interrupter switch and is operative to limit the closing movement of said manually operable control valve and the opening movement of said interrupter switch.

9. An automatic ignition and control apparatus as defined in claim 6 in which said means includes a detent operatively associated with said manually operable main control valve and said interrupter switch and which may be moved into and out of operative position and when in operative position limits the closing movement of said manually operable control valve and the opening movement of said interrupter switch.

10. In an automatic ignition and control apparatus of the character described the combination of a main burner, a pilot burner operable to ignite said main burner, an electric ignition element operative when energized to ignite said pilot burner, a gaseous fuel supply manifold, a main conduit through which fuel is supplied to said main burner from said manifold, a manually operable control valve interposed in said conduit between said main burner and said manifold, a safety control valve mechanism operative to cut off the supply of fuel to said main burner and said pilot burner interposed in said conduit between said manually operable control valve and said manifold, a secondary conduit extending between said safety control valve mechanism and said pilot burner through which fuel is supplied to said pilot burner, a solenoid operatively connected to said safety control valve mechanism, said solenoid being operative upon energization to first set said safety control valve mechanism in condition to supply fuel to said pilot burner while cutting off the supply of fuel to said main burner and upon subsequent deenergization to set said safety control valve mechanism in condition to also supply fuel to said main burner, an electromagnet associated with said safety control valve mechanism and operative when energized to maintain said safety control valve in said last set condition, a thermocouple adapted to be heated by said pilot burner, an electric circuit between said thermocouple and said electromagnet through which said magnet is energized by said thermocouple when said thermocouple is heated, an interrupter switch having two closed positions interposed in said circuit and operative to open and close said circuit and thereby control the energization of said electromagnet, operative connections between said manually operable control valve and said interrupter switch through which said interrupter switch is closed and opened by the opening and closing of the manually operable control valve, a normally open master switch having two closed positions associated with said manually operable control valve, operative connections between said manually operable control valve and said master switch through which said master switch is closed by the opening in said main control valve and is opened by the closing of said main control valve, said master switch being operative when closed to energize said solenoid and said electric ignition element, a normally closed switch disposed in series with said master switch which is operative when opened to de-energize said solenoid and said electric ignition element, means responsive to said pilot burner and operative to maintain said normally closed switch open while said pilot burner is ignited, a supplemental master switch disposed in series with said master switch and said normally closed switch when said master switch is in one of its closed positions, a supplemental interrupter switch interposed in said circuit in series with said interrupter switch when said interrupter switch is in one of its closed positions, and a time control mechanism operative to simultaneously close and open said supplemental master switch and said supplemental interrupter switch at predetermined set times.

RICHARD L. PERL. JOHN M. HOFF.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,303,672 Wantz Dec. 1, 1942 2,353,042 Koch July 4, 1944 2,478,386 Gauger Aug. 9, 1949 2,483,191 Gauger Sept. 27, 1949 2,562,536 Mayer July 31, 1951 2,564,869 Weber Aug. 21, 1951 2,577,787 Mayer et al. Dec. 11, 1951 2,578,717 Mayer et al. Dec. 18, 1951 2,578,718 Mayer Dec. 18, 1951 2,584,147 Mayer Feb. 5, 1952 

